Apparatus for constructing tanks



March 12, 1963 H. G. ABBOTT ETAL 3,089,843

APPARATUS FOR CONSTRUCTING TANKS March 12, 1963 H. G. ABBOTT ETAL APPARATUS FOR CONSTRUCTING TANKS 3 Sheets-Sheet 2 Filed April 16, 1958 47m/WE y March 12, 1963 H. G. ABBOTT ETAL 3,080,843 APPARATUS FKOR CONSTRUCTING TANKS Filed April 16, 1958 I5 Sheets-Sheet 5 l f l INVENTORS /wer G ,4166077 j l A@ United States Patent O This invention relates to the art of tank construction and particularly to that class of hollow vessels for transporting or storing liquid or other materials Iand including as a part thereof, a shell surrounding end walls and/or internal bulkheads or other reinforc-ing members to present an elongated, tu-bular structure ordinarily disposed horizontally when mounted on mobile vehicles such as trucks and semi-trailers.

Heretofore it has lbeen the common practice, utilizing conventional fabrication methods and apparatus, to follow a time-consuming, expensive procedure of cutting a plurality of sections into preselected shapes, bending or otherwise forming such sections into proper arcuate contours and thereupon attaching the sections one by one into place to the bulkheads and to each other, usually by welding but oftentimes through use of rivets or other fasteners.

It is the most important object of the instant invention,

therefore, to eliminate the aforementioned steps and to provide a construction method, as well as apparatus therefore, which permits the use of a single unitary, initially flat panel to form the shell of the tank and made from stock material, i.e., sheet sections Ithat are ordinarily rectangular in shape and welded together in a flat condition with-out need for cutting Ior forming prior to mounting of the panel on the heads or ends of the tank.

Ano-ther important object of the present invention is -to provide a method o-f the aforementioned character which is advantageous from the standpoint of saving in time, inasmuch as the method contemplates the rolling of the panel or the wrapping of the same around the tank ends and/or Iaround the false internal bulkheads,

vwhich rolling not only forms the panels into the tubular configuration Iof the shell, but permits Workmen to quickly and easily attach the panel, as by welding, to the various `bulkheads yand other supports while the rolling step is performed, to the end that the tank is virtually completed by the time the longitudinal edges of the panel are brought into juxtaposition.

Another extremely important object of the instant invention is to incorporate within the apparatus for carrying out the novel method, ya rather large number of various rearrangement factors, permitting the method to be used irrespective of the length of the tank, its diameter or transverse configuration so that, for example, the tank may be made transversely circular, elliptical or other shape, and so that the tank may either be truly cylindrical, truste-conical, lor any number of modiiications of such design characteristics.

lStill another important object of the instant invention is to provide apparatus which will permit carrying out the method in a minimum amount of time by virtue of the fact that the ends of the tank are used as rotatable supports during the carrying out of the method, and such ends subsequently become an integral part of the nished tank after the latter is removed from the forming apparatus. In this respect, therefore, rotatably supported wheels or the like in conjunction with chu-ck means, are employed to mount and support the ends of the tank and thereupon the panel itself is advanced to wrap the same around the tank ends as the latter are caused to freely rotate with the supporting wheels and chuck means therefor.

3,080,843 Patented Mar. 12, 1963 Fice Many important details of construction constitute additional objects of the present invention, all of which will be made clear or become apparent as the following specific-ation progresses.

In the drawings:

IFIG. la is a fragmentary, side elevational view of one end of one form of novel Iapparatus forming the subject matter `'of the instant invention and capable of carrying out the method above analyzed, showing in vertical section -a portion of a tank partially completed.

FIG. 1b is a fragmentary view similar to FG. la showing the opposite end of the apparatus.

FIG. 2 is a view showing that end of the apparatus illustrated in FIG. la; `and IFIG. 3 is a fragmentary, vertical, cross-sectional view taken on line 2 2 of FIG. la.

The apparatus illustrated in FIGS. la and Ib includes a pair of spaced, substantially identical supporting assemblies 10 and 12. The assembly 10 includes a pair of spaced, substantially triangular uprights 14 and 16 interconnected at the upper ends thereof by a crossbeam 18 and mounted rigidly on a chassis broadly designated by the numeral 20. The chassis 20 is in turn provided with grooved wheels 22 and 23 normally supported by V- shaped tracks 24 for bodily movement of the entire assembly 10 toward and away from the assembly 12.

Each upright 14 `and 16 is provided with an elongated slot 26 (see FIGS. 2 and 3) traversed by an elongated, rotatable shaft 28 that has its longitudinal axis substantially horizontal.

Shaft 28 is in turn supported by an open, rectangular 4frame 30 -angularly disposed as shown in FIG. 2, and embraced by the uprights 14 `and 16 as seen in FIG. la. Sides 32 of the frame 30 are likewise provided with longitudinal slots 34 which receive bearings 36 for the shaft 28. Bearings 36 are freely slidable in the slots 34 longitudinally thereof, but are anged as seen in FIG. la, to hold the latter against displacement from the sides 32 in -a direction longitudinally of the shaft 28.

Chassis 20 is provided with a stub shaft 38 (FIG. 2) parallel with shaft 28, journaling the lower end of the frame 30 for swinging movement about the substantially horizontal axis of the stub shaft 38. Power means for swinging the frame 30 takes the form of a hydraulic piston and cylinder assembly 40, pivotally connecting the chassis 20 with one o-f the sides 32 of the frame 30.

Bearings 42 for the shaft 28 are provided with spaced plates 44 embracing the shaft 28 and slidable longitudinally of the slots 26. Elongated bars 46 embracing each bearing 42 respectively, and attached thereto by bolts 48 threaded through the bars 46 and into the bearings 42, are releasably attached to the uprights 14 and 16 by bolts 50. Note in FlG. 2 that the uprights 14 and 16 are provided with two rows of tapped openings 52 alongside the slot 26 for receiving the bolts 50.

Shaft 28 is longitudinally slidable within the bearings 36 and 42, and its extent of reciprocation is limited by clamps 54 on the shaft 28 alternately engageable with the proximal bearings 42. Reciprocation of the shaft 28 is effected through use of a hydraulic piston and cylinder unit 56 pivotally interconnecting the upright 14 and a bracket 58 attached to a collar 60 on shaft 2S confined between the proximal clamp 54 and end plate 62 on shaft 28. A sliding follower 57, receiving the inner end of unit 56, may be connected with the proximal bearing 42 in any suitable manner for reciprocation therewith in the slot 26 of upright 14.

A mounting unit, broadly designated by the numeral 64, includes a wheel 66 having an inner rim 68 and an outer rim 70 concentric with the rim 68 and axially oiset with respect thereto. Rim 68 is attached to hub 72 4thereon in the manner best seen in FIG. 1a.

A hand wheel 8S is rigidly secured to the screw 34V to permit removal of the latter from the shaft 28, and a hand wheel 96 on the opposite side of hub 82 is threaded on the screw 84 and serves as a meansV for shifting the chuck means 7S toward the tank end S0 to clamp the latter tightly against the rims 68 and 70. Y

A plurality of tubes 92 radiating from the hub 82, slidably receive elongated rods 94 (see also FIG. 3) releasably held in place by setbolts or the like 96 in the tubes 92. Certain of the Yrods 94 are provided with shoes or pads 98 that bear against the concave face of the tan-k end 80, as well as against the annular inturned llange 100 The remaining alternate rods 94 have transverse studs 1(12 adjustably threaded therein and which also bear against the tank end 8d. A plumb rod 164, freely swingable on the screw 84 between the hand wheel 88 and the hub 82, is employed for aligning purposes hereinafter explained.

Chassis may be tilted about the axles of the wheels 23 as a fulcrum, raising the wheels 22 off the tracks 24' and attaching the chassis 20 to the tracks 24 to hold it against movement along such tracks 24 through use of a pair of jacks. Each jack 1116 includes a screw 108 piv otallyattached to a clamp 11@ on track 24 and extending through a sleeve 112 rigid to chassis 20. Opposed nutsYY 114 bearing against opposite ends of the sleeve 112 are threaded on the screw'llit. j

A power unit broadly designated by the numeral 1116, is carried by the chassis 20 for advancing a panel 118 that is initially llat and horizontally disposed, as best seen in FIG. 3. Unit 116 includes opposed rollers 120 and 122 receiving the panel 118 therebetween, roller 120V being preferably in the nature of a peripherally knurled disc, and roller 122 desirably being made from'some'- what resilient antifriction material such as hard rubber.

Roller 12b is mounted on one end of a drive shaft 121i which constitutes the output shaft'of an adjustable speed reducer 126 that is in turn coupled with an electric motor 128.v The bearings for shaft 124, the speed reducer 126 and the motor 128, are all mounted within the bight of an elongated, upwardly facing, transversely U-shaped channel 131? carried by the chassis 26 for vertical swinging movement about a fulcrum pin 132 intermediate 'the ends of the channel r130 therebeneath. Pin 132 is suspended from the chassis Y2(1) and may, therefore, Abe raised As above indicated, virtually all or" the above described components of the assembly 1d, are also included in the assembly 12. Oner difference is elimination or" tracks 24 and wheels 22 and 23 in the assembly 12j. ln lieu thereof, the Vassembly 12 is supported by pads 150' and 152 that are preferably rigidly mounted to horizontal supporting surface 154i. Legs 156, depending from chassis 158, are pivotally secured to the pads 152 for vertical tilting movement of the assembly 12. Noteworthy at this juncture is that the assembly 12 tilts about trunnions 1611 at the outer end of assembly 12, whereas the assembly 10 tilts about the axles of wheels 23 adjacent the inner end of assembly 10.

Jack 4means 162, which may be identical in nature to the jacks 106, are provide-d :adjacent the inner end of the assembly 12 for raising and lowering the latter, and are` pivotally connected with the pads 150. Mounting unit 164 for tank end 166, is essentially the same as the unit '64, but since the tank chosen for illustration is frustoyconical and, therefore, the end 166 is appreciably Smaller in diameter than the tank end 8l), it is necessary to use but va single annular rim 168 for wheel 170 forming a part ,of

the unit 164.

The tank constructing method of the instant invention employing the apparatus above described, is particularly advantageous in the production of tanks made from me tallic materials such as relatively heavy gauge steel lor other metals. The metallic sheets for making the panel 118 are ordinarily manufactured in Ia rectangular form and, therefore, it is but necessary to lay out the panel 118 by welding such rectangular sheets together prior to placing the apparatus illustrated in Ithe drawings, in use. In the manufacture of a cylindrical tank, lsuch panel 118 may be rectangular and right-angular throughout. When a frusto-conical tank is to be produced, asillustnated in the drawings, the trailing longitudinal edge of panel 118 Y (not showin) is manifestly cut at an angle, butit is to'be channel 130 which projects beyond the chassis 2t) to- -ward the Vroller 126, as seen in FIG. la, is 'adjustably clamped between opposed studs 13S mounted on the chassis 29. Retrograde rotation of the roller 1211 is prevented through use of any suitable pawl and ratchet mechanism broadly designated 14d.

Roller ,122 is mounted on an idler shaftldZ whose preferred that the leading longitudinal edge 172 of panel 118, be perpendicular to end edges 174 and 176 of panel 118. Y

I Panel 118 is thereupon laid horizontally upon a numberf of suitable pedestal-s 178 and threadedbetween therollers Thereupon, the hand wheels 14S are manipulated to Y clamp theV rollers 120 and 122 tothe panel 118Vand 'the latter isattached rigidly to the llange 1118r of tank en-d Sil, as well as to the corresponding'iiange of end'166, as by welding. Similarly, tanks of this nature are ordinarily provided with a series of internal members 180, serving various purposes such as to compartment the tank or, merely as reinforcements.'v Accordingly, such false bulkheads 1801 may either kbe ring-shaped orY in lthe nature of Clisc-like partitions having annular peripheries `or other.- Wise conforming in shapeto the transverse configuration of the tank. 'ifhe panel 11S is alsowelded to theperipheries of such mem-bers 1gb at the inner face of panel 118 adjacent the leading edge 172. Any suitable` temporary bracing (not shown), may be provided forfthe member 18) during the initialstages ofthe use of .the apparatus to hold members 130 in proper-"relationship tothe panel and to the ends Si! and 166. f Y

The motors 116.1are thereupon Venergized to drive the rollers and thereby advance ther-panel 118Ytran'sversely of the latter towandjundevrlying support and guiderollers l182, panel 118 sliding horizontally along the pedestals 17S Y and Itaking the form of the peripheries of the ends 3G 180 of the tank. Panel 118 is shown partially formed into the arcuate configuration of the tank in FIGS. 1a, 1b and 3.

During the rolling or Wrapping step of the method, it is to be preferredl that Ithe inner face of the panel 11S be attached from time to time, or continuously as by welding, to the heads 80 and 166, as well as to the members 180. In this respect, tank welding is usually suiicient, but conceivably, automatic, continuous welding without interruption of the rolling or wrapping procedure, may be employed to an advantage. And, of course, the method of the instant invention contemplates .other means of attachment such as through use of rivets or other fasteners.

After the panel 118 has been completely Wrapped around the internal structure of the tank, the trailing edge (not sho-wn) of the panel 118, will meet with the leading edge 172 and such joint between the juxtaposed edges is thereupon closed, such as by welding. Excess material in the panel 118, now in the form of a shell and extending outwardly beyond the ends 80 and 166, may be removed through use of a cutting torch or other means of severance.

Tanks :of this nature are ordinarily provided with one or more manholes, permitting Workmen to gain access -to the two chuck assemblies 78. These assemblies are released by removing the hand wheels 90 and thereupon, releasing the setbolts 96 to permit collapsing of the arms 94, whereupon the hub 82 may be removed from screw 84. Thereupon, through use of hand wheel 88, the screw 84 is removed from the shaft 28 and all of the parts, including plumb 104, may be removed from within the tank piece by piece. Subsequently, the openings 86 may be closed and if the members 180 are to serve as partitions, access openings provided therein, may likewise be closed by workmen operating within the tank.

After removal of the chuck means 7S, the wheels 66 and 179 may be retracted to permit removal of the tank from the supporting rollers 187i by actuation of the units S6 to shift the shafts 28 until the innermost clamp 54 en,- gage the proximal bearings 42.

The two motors 12S should be synchronized for simultaneous operation and the relative speeds of rotation of the drive rollers l2@ may be adjusted -by altering the corresponding speed reducers 126. Here again, it is seen that such relative speeds depend upon the relative diameters of the ends 80 and 166 of the tank. Manifestly, any automatic synchronization between the two power units 116, should be arranged to assure that leading edge 172 remains parallel with the longitudinal axis of the tank throughout the time such edge moves through its 360 degree cycle.

Obviously, the heights of the shafts 2S which may be adjusted through use of the power assemblies dit, depends upon the diameters of the two ends 8@ and 166 whether such diameters are to be identical or differing as shown. Similarly, the longitudinal axes of the shafts 2S must be in precise alignment whether horizontal in the case of a cylindrical tank, or tilted in the case of the frusto-conical tank illustrated. Such adjustment is effected through us-e of the four jacks 166, 162, and the length of the tank determines the dis-tance between the assemblies 1G and 12 which may be varied by rem-oval of the clamps 110, permitting all four Wheels 22 and 23 to travel `along the tracks 2d.

Having thus described the invention what is claimed as new and desired to be secured by Letters Patent is:

1. Apparatus for making tanks from an elongated, initially hat, lunitary panel, said apparatus comprising a supporting chasis; a pair of spaced, supporting assemblies carg ried by the chassis, each having a mounting unit and normally yhorizontally disposed shaft structure for att-aching said unit thereto for rotation about the axis of the shaft structure, the axes of rotation of the units being aligned, each assembly having mechanism including a shiftable frame supporting said structure thereof for movement Cab transversely of said axes to shift said shaft structure with respect to said chassis to thereby var-y the diameter of the tank, each unit having chuck means for securing a tank end thereto with the tank ends joined at their peripheries to one face of the panel vadjacent one longitudinal edge of the latter; and means including a pair of pinch rollers` carried by said chassis in laterally spaced relationship to a corresponding unit, -below the corresponding structure and drivingly engageable with said panel for advancing the latter with respect to said chassis, said rollers being rotatable to rotate said units in the same direction, there being backing means adjacent the chassis and below the panel for engaging the panel as the same is advanced to wrap the panel around the peripheries of said ends to present a tubular shell closed by the tank ends.

2. Apparatus for making tanks from an elongated, initially lat, unitary panel, said apparatus comprising a supporting chassis; a pair of spaced, supporting assemblies carried by the chassis, each having a mounting unit and normally horizontally disposed shaft structure for attaching said unit thereto for rotation about the axis of the shaft structure, the axes of rotation of the units being aligned, each unit having chuck means for securing a tank end thereto with the tank ends joined at their peripheries to one face of the panel :adjacent one longitudinal edge of the latter; and means including a pair of pinch rollers carried Iby said chassis in laterally spaced relationship to a corresponding unit, below the corresponding structure and drivingly engageable with said panel for :advancing the latter with respect to said chassis, said rollers being rotatable to rotate said units in the same direction, there being backing means adjacent the chassis and below the panel for engaging the panel as the same is advanced -to wrap the panel around the peripheries of said ends to present a tubular shell closed by the tank ends, the chassis including elongated portions supporting said assemblies respectively, each portion being tiltable with respect to the other portion, whereby the shaft structure may be tilted, permitting the aligning of said axes for mak-ing tanks having ends of differing diameters.

3. Apparatus for making tanks from an elongated, iniitially hat, unitary panel, said apparatus comprising a supporting chassis; a pair of spaced, supporting assemblies carried by the chassis, each assembly including a slotted upright and provided with a substantially horizontal shaft in the slot thereof, means including a shiftable frame for mounting the shaft for vertical reciprocation within the corresponding slot and reciprocation along its longitudinal axis through said slot, power means coupled with the shaft for reciprocating the same along said longitudinal axis thereof, and power means coupled with the shaft for reciprocating the same vertically, cach shaft carrying a mounting unit rotatable about an axis coincident with said longitudinal axis of the shaft, the axes of rotation of the units being aligned, each unit having chuck means for securing a tank end thereto with the tank ends joined at their peripheries to one face of the panel adjacent one longitudinal edge of the latter; and means including a pair of pinch rollers carried by said chassis in later-ally spaced relationship to a corresponding unit, below the corresponding structure and drivingly engageable with said panel for advancing the latter with respect to said chassis, said rollers being rotatable to rotate said units in the same direction, there being backing means adjacent the chassis and below the panel for engaging the panel as the same is advanced to wrap the panel around the peripheries of said ends to present a tubular shell closed by the tank ends.

4. Apparatus for making tanks from an elongated, initially flat, unitary panel, said apparatus comprising a supporting chassis; a pair of spaced, supporting assemblies carried by the chassis, each having a mounting unit and normally horizontally disposed shaft structure for attaching said unit thereto for rotation about the axis of the nfrom Vsaid'one roiler. Y. i l ,l i 7. VApparatus `for making tanks `from an elongated, iniassente rotatable to rotate said units in the sa-me direction, there` being backing means adjacent the chassis and below the panel for engaging the panel as the same is advanced towrap the panel :around the peripheries of said ends to present a tubular shell closed by the tank ends, each as sembly having an outermost and an innermost end, the chassis including elongated portions supporting said assemblies respectively, each portion being tiltable with respect to the other portion, whereby the shaft structure may be tilted the outermost end of one assembly and the innermost end of the other assembly respectively, said portions being fulcrumed intermediate the ends thereof for vertical tilting movement, there being means on the chassis for tilting the portions and thereby said structures.

5. Apparatus for making tanks from an elongated, initially flat, unitary panel, said apparatus comprising a supporting chassis; a pair of spaced, supporting assemblies carried by the chassis, each having a mounting unit and normally horizontally disposed shaft structure for attaching said unit thereto for rotation about the axis of the shaft structure, the axes of rotation of the units being aligned, each unit having chuck means for securing a tank end thereto with the tank ends joined at their peripheries to one face of the panel adjacent one longitudinal edge of the latter, each assembly having :a pair of rollers tightly receiving the panel therebetween and'in driving engage ment with the panel for advancing the latter with respect to said chassis, said rollers being rotatable to rotate said units in the same direction, there being backing means adjacent the chassis and below the panel for engaging the panel as the same is advanced to wrap the panel around the peripheries of said ends to present a tubular shell closed by the tank ends, there being means onsaid chassis and coupled with one of the rollers thereof for driving the same, said chassis being shiftable for moving one of v Vthe assemblies and thereby the corresponding shaft and the corresponding pair of rollers away from the other assembly, whereby tanks of varying lengths may be constructed thereby.

6. Apparatus for making tanks from an elongated, Vinitially flat, unitary panel, said apparatus comprising a supporting chassis; a pair of spaced, supporting assemblies carried by the chassis, each h-avinga mounting unit and normally horizontally disposed shaft structure for attaching said unit thereto for rotation about the Vaxis of the Y shaft structure, the axes of rotation of the un-it'sibeing aligned, eac-h unit having Vchuck means forrsec'uring a tank end thereto with the tank ends joined at their peripheries toV one `face of the panel adjacent one longitudinal edge of the latter, each assembly having arpair of rollers receiving thepanel therebetween and in driving engagement Y with the panel for advancing the latter with respectl to said chassis, said rollers being rotatable to rotate said units in the sa;1 `e direction, there being backing means adjacent the chassis :and below the panel for envaging the panelras the same is advanced to wrap the panel around the peincluding a shaft pivotallyfmounted intermediate the ends V,thereofon said chassis and operably coupled with the other roller, said shaftbeing swingable in opposed directions to shift the other of the rollers towardV andraway 8 tiallytlat, unitary panel, said apparatus comprising a supporting chassis; a pair of spaced, supporting `assemblies carried by the chassis, each having a mounting unit and normally horizontally Idisposed shaft structure for attaching said unit thereto for rotation about the axis of the shaft structure, the axes of rotation of the units being aligned, each unit having chuck mems for securing a tank end thereto with the tank ends joined at their peripheries to one face of the panel adjacent one longitudinal edge of the latter, said chassis having a pair of rollers thereon adjacent each assembly and below the corresponding shaft structure, said rollers being disposed for receiving the l panel therebetween and in driving engagement with the panel for advancing the latter with respect to said chassis,v

said rollers being rotatable to rotate said units in the same direction, there being backing means adjacent the chassis and below the panel for engaging the panel as Vthe same is porting said assemblies respectively, each portion beingk tiltable with respect to the other portion, whereby the shaft structure may be tilted the outermost end of one assembly and the innermost end of the other assembly respectively, said portions being fulcrumed intermediate the ends thereof for vertical tilting movement, there being means on the chassis for tilting the portions and thereby said structures.

8. Apparatus for making tanks from an elongated, initially flat, unitary panel, said apparatuscomprising a supporting chassis; a pair of spaced, supporting,` assemblies carried -by the chassis, each having a mounting unit andV normally horizontally disposed shaft structure for attaching said unit theretok for rotation about the Vaxis of the shaft structure, the axes of rotation of the units Vbeing aligned, each unit having chuck means for securing a tank end thereto with the tank ends joined at Ytheir peripheries to one face of the panel adjacent one longitudinal edge of the latter, said chassis having a pair of rollersrthereon adjacent each assembly and below the corresponding shaft structure, said rollers being disposed for receiving the panel therebetween and in drivingengagement with the panel for advancing the latter with respect to said chassis, said rollers being rotatable to 'rotate said units in Y the same direction, there being backing means adjacent the chassis and below the panel for engaging the panel as i the Asame is advanced to wrap `the panel around the pe i ripheries of said ends to present a tubular shell closed byV the tank ends, each assembly having means coupled with one of the rollers thereof for driving the same, and means including arshaft pivotally mounted intermediate the ends thereof on said chassis and operably coupled with theV 'other roller, Vsaid shaft being swingable in opposed directions to'shift the other of the yrollers toward and away from saidiroller', each assembly havingfan outermost and .an inner-most end,-the chassis including 4elongated portions supporting said assemblies respectively, each portion being Vtiltable with respect `to the Yother portion, whereby the shaft structure may :be tilted, the Voutermost end of one assembly and the inner-most end of the other assembly re- A spectivelysaid portionsl being'fulcrumed intermediate the endsV t iereof for vertical tilting movement there being means on the chassis for tilting the portions and thereby said structuresQelach assembly having nreansfsupporting its Arollers and lits roller Ydriving Ameans forV vertical swingingV Y Vmovement as aunit independently of Y with its tilting movement;

(Re"erences on following page) and in parallelismA References Cited in the le of this patent UNITED STATES PATENTS Gray Nov. 12, 1935 10 Washburn et al Feb. 11, 1941 Wallis Oct. 16, 1945 Wiley et al. Jan. 7, 1958 FOREIGN PATENTS Great Britain` Dec. 19, 1938 

1. APPARATUS FOR MAKING TANKS FROM AN ELONGATED, INITIALLY FLAT, UNITARY PANEL, SAID APPARATUS COMPRISING A SUPPORTING CHASIS; A PAIR OF SPACED, SUPPORTING ASSEMBLIES CARRIED BY THE CHASSIS, EACH HAVING A MOUNTING UNIT AND NORMALLY HORIZONTALLY DISPOSED SHAFT STRUCTURE FOR ATTACHING SAID UNIT THERETO FOR ROTATION ABOUT THE AXIS OF THE SHAFT STRUCTURE, THE AXES OF ROTATION OF THE UNITS BEING ALIGNED, EACH ASSEMBLY HAVING MECHANISM INCLUDING A SHIFTABLE FRAME SUPPORTING SAID STRUCTURE THEREOF FOR MOVEMENT TRANSVERSELY OF SAID AXES TO SHIFT SAID SHAFT STRUCTURE WITH RESPECT TO SAID CHASSIS TO THEREBY VARY THE DIAMETER OF THE TANK, EACH UNIT HAVING CHUCK MEANS FOR SECURING A TANK END THERETO WITH THE TANK ENDS JOINED AT THEIR PERIPHERIES TO ONE FACE OF THE PANEL ADJACENT ONE LONGITUDINAL EDGE OF THE LATTER; AND MEANS INCLUDING A PAIR OF PINCH ROLLERS CARRIED BY SAID CHASSIS IN LATERALLY SPACED RELATIONSHIP TO A CORRESPONDING UNIT, BELOW THE CORRESPONDING STRUCTURE AND DRIVINGLY ENGAGEABLE WITH SAID PANEL FOR ADVANCING THE LATTER WITH RESPECT TO SAID CHASSIS, SAID ROLLERS BEING ROTATABLE TO ROTATE SAID UNITS IN THE SAME DIRECTION, THERE BEING BACKING MEANS ADJACENT THE CHASSIS AND BELOW THE PANEL FOR ENGAGING THE PANEL AS THE SAME IS ADVANCED TO WRAP THE PANEL AROUND THE PERIPHERIES OF SAID ENDS TO PRESENT A TUBULAR SHELL CLOSED BY THE TANK ENDS. 